#include<bits/stdc++.h>
using namespace std;

void QuickSort(int a[],int low,int high){
    while(low<high){
        a[0] = a[low];// pivilot key
        if(a[high]<a[0]){
            a[low] = a[high];
        }else{
            high--;
        }
        if(a[low]>a[0]){
            a[high] = a[low];
        }else{
            low++;
        }
    }
}